Field of the Invention
The present disclosure relates to a method for producing a field-effect transistor.
Description of the Related Art
As one example of a field-effect transistor, a field-effect transistor using an oxide semiconductor in an active layer is known (see, for example, Japanese Patent No. 5118811).
For improvements in performances and operation stability of transistors, it is required to homogeneously form a front channel interface and a back channel interface to reduce defect density. For example, a method using an etching stopper layer has widely been used as a method of reducing defect density of a back channel by preventing an oxide semiconductor from receiving damage from an etchant during patterning of a source electrode and a drain electrode.
In recent years, a method of producing a field-effect transistor using a coating method has been proposed (see, for example, Japanese Unexamined Patent Application Publication No. 2009-177149).
In cases where the coating method is used for formation of a front channel or a back channel, the method using an etching stopper layer cannot homogeneously form the front channel interface and the back channel interface in some cases.